1. Field of the Invention
The present invention relates to a winder and a method for continuous winding of a material web, specifically a paper or cardboard web.
2. Description of the Related Art
Methods and winders such as disclosed in European patent publication EP 0 483 092 B1 or document PCT-WO 98/52858 A1 (PR10706 WO) are used in machinery for the production or converting of material webs, for example paper or cardboard webs.
Today""s modern winding concepts employ contact pressure devices including either a hard cylindrical reel drum or a reel drum displaying negligible deformation characteristics. When utilizing these contact pressure devices a precise progression of the line force between reel drum and winding roll cannot always be ensured due to unevenness of the progression of the line force between carrier roll and winding roll, particularly in light of the desire that no trapping of air occur between the individual layers of the winding roll. In addition, considerable problems occur in the intended maintenance of the xe2x80x9cwound inxe2x80x9d web tension, specifically in maintaining the desired winding quality in the outer area of the wound roll. The problems arising in this context increase with increasing winder speed (1,500 to 2,500 m/min.) and with an increasing diameter of wound rolls (2.5 to 4.5 m).
A winder is disclosed in European patent documentation EP 0 369 977 (U.S. Pat. No. 5,026,005), whose rigidly mounted reel drum includes at least one winding cylinder which is equipped with at least one device for adjustment of the deflection of the cylinder shell, whereby at least one device is mounted inside the winding cylinder""s shell. The presence of this at least one device creates the feasibility of controlling the distribution of the linear load in the winding nip during the winding process. The control possibilities however, are very limited, due to constructive factors. Such a device cannot ensure that no air entrapment occurs between the individual layers in the wound roll, nor can it ensure that the xe2x80x9cwound inxe2x80x9d web tension is maintained, in order to obtain the desired winding quality in the outer area of the wound roll.
A winder is also disclosed in the aforementioned document PCT WO 98/52858 A1 (PR10706 WO), which includes a movable reel drum. This movable reel drum is relatively light when compared to the weight of the increasingly larger wound roll, allowing rapid xe2x80x9cstabilizingxe2x80x9d of long-wave diameter variations in the wound roll. Short-wave diameter variations however, cannot be satisfactorily xe2x80x9cstabilizedxe2x80x9d.
What is needed in the art is a method and a winder which will provide a precise adjustment and control of the progression of line force between the reel drum and the wound roll despite unevenness in the surface contour of the wound roll, ensuring that no air entrapment occurs between the individual layers in the wound roll.
The present invention provides a method and winder that controls and adjusts the line force progression in the winding nip across the reel drum in individual zones. Long-wave diameter variations in the wound roll which influence the progression of the line force in the winding nip are compensated by relocation of the reel drum. In contrast, short-wave diameter variations in the wound roll, which influence the progression of line force in the winding nip, are compensated for by at least one support element of the reel drum which is constructed as a deflection compensation roller. The relocation of the reel drum and support element(s) provides the opportunity to control long-wave and short-wave diameter variations in the wound roll to avoid air entrapment between the individual layers of the wound roll and to maintain the xe2x80x9cwound inxe2x80x9d tension during the entire winding process.
In one embodiment of the invention a winder includes a reel drum that is moveable by means of a contact pressure device. The pope roll is a deflection compensation roll whose roll shell is supported on a stationary cross shaft by means of a row of side by side support elements. This allows the progression of the line force in the winding nip to be adjustable through the relocation of the reel drum and/or at least one support element.
The controllability and the winder""s high winding quality is established, in one embodiment of the present invention, with support elements which are effective in the direction of the winding nip, and whose position is changeable.
During the various winding phases (initial winding phase, main winding phase, end winding phase) one embodiment of the present invention includes a cross shaft that can be pivoted so that the effective direction of the support elements track with movements of the winding nip. This embodiment verifies, adjusts and controls the critical winding phases throughout the winding process.
The support elements may be adjustable and controllable in their entirety, in sections, in groups and/or individually. The sensitivity of the winder is based on the sophistication of the adjustment devices and controllers. In one embodiment of the present invention the two edge areas of the reel drum are equipped with a larger number of support elements having smaller support widths. The support elements can be arranged in sections which are independent from each other or in various inter-independent groups, and may be configured in mirror image or overlapping zones. Generally, any combination of support elements in any desired number may be utilized.
Based on design, cost and operational aspects, the adjustment and control of the support elements occurs by means of a hydraulic system with an associated control unit. Such hydraulic systems have proven themselves suitable in other applications in a paper or cardboard machine. Hydraulic fluid may also be used as a lubricant for the gliding surfaces of the support elements. The control unit may utilize piezo quartz sensors integrated into the gliding surfaces of the support elements.
In yet another embodiment of the invention support elements have a supporting width of 25 to 500 mm, preferably of 50 to 250 mm; and they have a support stroke of 150 to 400 mm, preferably of 200 to 300 mm. The cross shaft will have a length of 500 to 800 mm, preferably 600 to 750 mm. The reel drum will have an inside diameter of 1,000 to 1,250 mm, preferably 1,100 to 1,200 mm and it will have an outer diameter of 1,300 to 1,500 mm, preferably 1,350 to 1,450 mm. These dimensional ranges afford the possibility under the aforementioned aspects, to operate an optimally functioning winder with good runability and at low cost.
It is understood that the aforementioned characteristics of the invention which will also be described further in the following, may be used not only in the cited combination, but also in other combinations or standing alone, without leaving the scope of the invention.